The present invention relates generally to imaging procedures. Particularly, the present invention relates to a method for improving computer aided detection or diagnosis by utilizing a computer aided processing technique.
Computer aided diagnosis (CAD), such as screening mammography and evaluation of other disease states or medical or physiological events, is typically based upon various types of analysis of a series of collected images. The collected images are analyzed by utilizing the pathologies that are highlighted by a CAD algorithm. The results are generally viewed by radiologists for final diagnosis. As can be appreciated by those skilled in the art, certain subsequent imaging procedures may become feasible or may be recognized as desirable due to the improved management of data volume.
It should be noted that computer aided CAD may be utilized in any imaging modality, such as computed tomography (CT), magnetic resonance imaging (MRI), X-ray systems, ultrasound systems, positron emission tomography (PET), and so forth. CAD algorithms in certain of these modalities may provide advantages over those in other modalities, depending upon the imaging capabilities of the modality, the tissue being imaged, and so forth. Computed tomography, for example, is generally a diagnostic procedure in which cross-sectional images or slices are made by an X-ray system. The CT scanning procedure combines the use of a computer system and a rotating X-ray device to create detailed cross sectional images or xe2x80x9cslicesxe2x80x9d of a patient""s organs and other body parts. The imaging capabilities are physically similar to those of X-ray systems. MRI, ultrasound, PET, and other modalities similarly are adapted to imaging certain tissues or anatomies, and provide advantages for the different CAD algorithm employed with images they produce.
Each imaging modality is based upon unique physics and image processing techniques. For example, a CT system measures the attenuation of X-ray beams passed through a patient. from numerous angles, and then, based upon these measurements, a computer is able to reconstruct images of the portions of a patient""s body responsible for the radiation attenuation. As will be appreciated by those skilled in the art, these images are based upon separate examination of a series of continuous cross sections. Thus, a virtual 3-D image may be produced by a CT examination. It should be pointed out that a CT system does not actually directly provide an image, but rather numerical values of tissue density. The image based upon the reconstructed data is typically displayed on a cathode ray tube, and may be printed or reproduced on film.
Continuing with the example of CT imaging, CT scanners operate by projecting fan shaped X-ray beams from an X-ray source that is collimated and passes through the object, such as a patient, that is then detected by a detector element. The data is then used to produce a useful image. Thus, the detector element produces data based on the attenuation of the X-ray beams, and the data are processed by computer analysis. The locations of pathologies may then be highlighted by the CAD algorithm, and thus brought to a human observer""s attention. The results may then be reviewed by a radiologist or other physician for final diagnosis.
Each imaging modality may provide unique advantages over other modalities for certain types of disease or physiological condition detection. For example, CT scanning provides advantages over other types of techniques in diagnosing disease particularly because it illustrates the shape and exact location of organs, soft tissues, and bones any slice of the body. Further, CT scans may help doctors distinguish between a simple cyst, for example, and a solid tumor, and thus evaluate abnormalities more accurately. As mentioned above, other imaging modalities are similarly best suited to imaging other physiological features of interest, and to corresponding CAD algorithms.
Existing techniques for computerized diagnosis of physiological features suffer from certain serious drawbacks. For example, the output of the CAD analysis is generally fairly, interactive, requiring assessment and evaluation by a seasoned practitioner. Due to time constraints and the availability of such persons, a patient is often called upon to report for certain types of examination, with further examinations needing to be scheduled, when appropriate, based upon the review of the CAD analysis. That is to say, patients often must return for additional tests on the same or a different modality imaging system in order to properly evaluate and diagnose potential conditions. The resulting procedure is not only time-consuming for the patient and for the physician, but ultimately results in the entire process extending over a considerable period of time. Additional appointments for subsequent imaging can also result in considerable expense both for the patient, for hospitals and clinics, and for insurance carriers.
There is a need, therefore, for improved technique for guiding subsequent image data acquisition based upon analysis by a CAD algorithm. There is a particular need for a technique which would allow additional data to be prescribed and acquired both from the same or from the same type of imaging system as used in initial evaluations, and from other modality systems, where appropriate.
The present technique provides an improved method for useful medical images for diagnosing patients that responds to such needs. The technique makes use of initial CAD information to guide additional data acquisition with or without additional human operator assistance. Thus, once a feature of interest is identified by the CAD algorithm a computer may automatically direct the imaging system to re-acquire additional images at the suspected location, or may instruct or suggest that an operator do so.
In accordance with one aspect of the invention, a method is provided for processing an image generated by an imaging system. The method includes acquiring a first series of images from a first imaging system. The first series of images is then processed in accordance with a CAD algorithm. A second series of images is then acquired based upon the results of the CAD algorithm.
In accordance with another aspect of the invention, an imaging system includes a first image data acquisition system configured to acquire medical images, and a computer system. The computer system is coupled to the image data acquisition system and is configured to generate a first series of images from image data acquired by the acquisition system. The computer system is further configured to process the first series of images via a CAD algorithm. The computer system is configured, as well, to prescribe acquisition of a second series of images based upon results of the CAD algorithm.